Posts Tagged ‘post’

Improve MobaXterm Best Windows terminal client with some additional settings tune ups / Install extra Linux Cygwin tools on MobaXterm and various post install configuration goodies

Friday, January 20th, 2023


Earlier I've written a an article MobaXTerm: A good gnome-terminal like tabbed SSH client for Windows / Windows Putty Tabs Alternative in which I've introduced the best in my opinion SSH / Telnet / VNC / RDP / Xserver in one Terminal client emulator for Windows operating systems.

The client has been around for quite some time and it has been improving rapidly over the last 10 years, where it now more looks like a separate Operating System than a single terminal client. It's size is quite compact as well and my opinion and every self respectiving developer, system administrator, IT geek or a hacker would definitely
use the mobaxterm at home or at work place on a daily. I guess some of my readers, who have already migrated SuperPutty / SecureCRT or Putty / XMing or whatever kind of exotic Remote SSH Console terminal is used could validate this 🙂

Therefore as I've set up Mobaxterm on a multiple computers all around, I've found it useful to write a small article with some post-install hints (tune ups) one can do immediately once he has installed the Desktop or Portable Apps version of mobaxterm on desktop PC / notebook.

1. Set up your bashrc server / command aliases

Lets say you need to setup some rules for connectivity via a socks proxy to dig holes over a harsh company firewalls or add
custom options to every ssh client attempt to remote server, or simply alias some of your servers with custom connectivity options
and so on simply open vi / vim text editor from mobaxterm local terminal and place inside your rules, for example that could be anything like:


alias ssh='ssh -o stricthostkeychecking=no -o passwordauthentication=yes -o PreferredAuthentications=password  -v'
alias sftp='sftp -o stricthostkeychecking=no -o passwordauthentication=yes -o PreferredAuthentications=password'

alias work-server='ssh UserName@work-server -v -o passwordauthentication=yes -o PreferredAuthentications=password'

alias proxy='ssh -D 3128 UserName@proxyIP-host1 -o ConnectTimeout=80'
alias proxy1='ssh -D 3128 UserName@proxy-host2 -p 443 -o ConnectTimeout=60'
alias proxy3='ssh -D 3128 Username@proxy-host3 -p 443 -o ConnectTimeout=60'

Simply open the terminal and setup whatever you require
export ftp_proxy="http://proxy-host:8080"
export https_proxy="https://proxy-host:8080"
export http_proxy="http://proxy-host:8080"
export HTTP_PROXY="http://proxy-host:8080"
export HTTPS_PROXY="http://proxy-host:8080"


2. Set mobaxterm presistent directory / persistent root directory and default text editor

Make sure you have properly defined at least Persistent directory / Persistent directory if you want to keep the files under your /home/mobaxterm and root directory be able to save your data from local mobaxterm terminal work you have done.

To do so o to Configuration -> General


3. Change default settings for Opening / Closing Terminal tabs just like in gnome-terminal

MobaXterm is really awesome as the developer, followed pretty much the logic of some common GNU / Linux Terminal clients like Gnome-Terminal and KDE's default Konsole terminal.

One of the first things to do once Mobaxterm is installed on the PC is to set up nice key binds as default onces might be heard to learn at the beginning or you might have already the habit to use the certain set of key combinations on your Linux desktop:

Common once are:

1. Open tab / Close tab common once I bind to are (CTRL + T / CTRL + W)
2. Previous tab move / Next tab move keys common one I use are (ALT + LEFT / ALT + RIGHT)
3. Find in terminal (CTRL + F)


4. Make MobaXterm to automatically open a terminal to not Start local terminal every time

By default mobaxterm it is really annoying cause every time you run it after system reboot you have to select
Start local terminal
Once you run the terminal you get this prompt and you have to press on Start local terminal


How to make Mobaxterm automatically open local Terminal Tab on every boot?

To fix this so every time a local terminal is spawn on MobaXterm you have get to:

Settings -> Configuration -> Misc

Open the Following tab at startup by default it will be

<Home (Pinned)>

Change it to:



That's it on next login your Local Terminal with /bin/bash.exe will auto load !

[hipo.WINDOWS-PC] ➤ env|grep -i SHELL

5. Make menu buttons to appear smaller

Go to menu and select
View -> (Small Buttons)


6. Disable auto start of XServer to prevent a port listener on the machine on TCP port

By default mobaxterm opens XServer listener, so you can immediately connect from a remote SSH servers missing Xserver and install software requiring an XServer, for example software such as Oracle Database or some MiddleWare WebLogig or IBM's Web Sphere. This is useful but if you want to have a good security only allow this server on a purpose. Otherwise the XServer will run in parallel with rest of your Moba and just load up your PC and eat up some RAM memory. To disable it go to:


7. Change the mobaxterm Default theme to Dark

This is optional I like to set the Theme to Dark, also as a Theme for Windows as well as for MobaxTerm, the aim of that is simply to not put extra stress on my eye sight. Being on the PC around 8 to 10 hours and spending some 6 to 8 hours on console work is enough. If you want to do as well.


8. Install additional set of common Linux tools to mobaxterm to use on Windows

Tools such as:

1. Midnight Commander (mc)
2. Wget
3. Curl
4. Vim
5. Screen
6. Rsync
7. Perl
8. W3m
9. dosunix
10. unix2dos
11. gnupg
12. diffutils
13. mysql
14. mpg123
15. whois

If you want to have a set of packages pre-installed that are including above as well as the rest of mine, here is a dump of my installed mobapt manager packages:

For more simply use the experimental Mobaxterm  Graphical Package installer

[hipo.WINDOWS-PC] ➤  for i in $(cat Downloads/installed-packages-mobaxterm.txt ); do apt-cyg install $i; done

Found package GeoIP-database

Installing GeoIP-database
Downloading GeoIP-database-20180505-1.tar.xz…
Unpacking GeoIP-database-20180505-1.tar.xz…

Running postinstall scripts
Package GeoIP-database installed.

Rebasing new libraries

Found package adwaita-icon-theme

Installing adwaita-icon-theme
Downloading adwaita-icon-theme-3.26.1-1.tar.xz…

You will be prompted for a single Yes for the respository

MobApt Packages Manager


Though it is said it is experimental, I have to say the MobApt Apt Manager works quite good, I never had any issues with it so far.

9. Mobaxterm.ini the settings storage file that can help you move your configurations

If you have to prepeare new MobaXterm on multiple PCs frequently perhaps it is best to just copy the Mobaxterm.ini file. 
Here is an example of my mobaxterm.ini for download.

10. Change terminal colors and curor type and enable blinking (customizations)

Settings -> Configuration -> Terminal -> (Default Terminal Color Settings)


11. Use very useful moba Tools

For sysadmins Moba has plenty of other jems such as:

  • Network Port scanner such as Nmap with GUI

  • list open network ports (GUI interface to netmap)

  • SSH tunnel tool

  • Moba Diff

  • Wake on Lan

  • Network Packet capturer (such as tcpdump)

  • List running processes (such as taskmgr in simple form)

  • List machine hardware devices (such as Windows Device manager)

12. Remote monitoring of opened ssh session

To enable remote monitoring for a Saved session simply use the "Remote monitoring" button on the down left corner of the terminal.


Or to enable it for a new host, open:

1. "Saved sessions"
2. Click over "User sessions"
3. New Session -> (SSH)
4. Basic SSH Settings (Remote host) -> OK
5. Click over the new created session
6. Click on Remote monitoring for the opened session


13. Play some mobaxterm console games

As you might have pissed off of configuring go on and enjoy some of the great console games, some of which are also present on a normal Linux new distribution installation. 🙂


List of Moba Games

TeamWalk (Use your mouse or keyboard to connect every server to the central router)


Ctris Console tetris from Mobaxterm


Text console Solitaire from Moba


Here is NinVaders (Text Version of Space Invaders Arcade Classic)

Enjoy ! 🙂

Upgrade old crappy Windows 7 32 bit to Windows 10 32 bit, post install fixes and impressions / How to enter Safe Mode in Windows 10

Wednesday, June 28th, 2017


However as I've been upgrading my sister's computer previously running Windows 7 to Windows 10 (the process of upgrading is really simple you just download Windows-Media-Creation-tool from Microsoft website and the rest comes to few clicks (Accept Windows 10 User Agreement, Create current install  restore point (backup) etc.) and waiting some 30 minutes or so for the upgrade to complete.


Then it was up to downloading some other updates on a few times and restarting the computer, each time the upgrades were made and all the computer was ready. I've installed Avira (AntiVirus) as I usually do on new PCs and downloaded a bunch of anti-malware (MalwareBytes / Rfkill  / Zemanta)  to make sure that the old upgraded  WIndows was not already infected before the upgrade and I've found a bunch of malware, that got quickly cleared up.

Anyways I've tried also another tool called ReimagePlus – Online Computer Repair in order to check whether there are no some broken WIndows system files after the upgrade

(here I have to say I've done that besides running in an Administrator command prompt (cmd.exe) and running

sfc /scannow

command to check base system files integrity, which luckily showed no problems with the Win base system files.

ReimagePlus however showed some failed services and some failed programs that were previously installed from Windows 7 before the upgrade and even it showed indication for Trojan present on computer but since ReImagePlus is a payed software and I didn't have the money to spend on it, I just proceeded to clean up what was found manually.

After that the computer ran fine, with the only strange thing that some data was from hard drive was red a bit too frequently, after a short call with a close friend (Nomen) – thx man, he suggested that the frequenty hdd usage might be related to Windows Search Indexing service database rebuilt and he adviced me to disable it which I did following this article How to speed up Windows by disabling Search Index Service.

One issue worthy to mention  stumbled upon after the upgrade was problems with Windows Explorer which was frequently crashing and "restarting the Desktop", but once, I've enabled all upgrades from Microsoft and Applied them after some update failures and restarts, once all was up2date to all latest from Microsoft, Explorer started working normally.

In the mean time while Windows Explorer was crashing in order to browse my file system I used the good old Win Total Command or Norton Commander for Windows – WinNC (with its most cool bizzarre own File Explorer tool).


As I wanted to run a MalwareBytes scan and Antivirus under Windows Safe-Mode, I tried entering it by restarting the Computer and pressing F8 a number of times before the Windows boot screen but this didn't work as Safe-Mode boot was changed in Windows 10 to be callable in another way because of some extra Windows Boot speed up optimizations, in short the easiest way I found to enter Windows 10 Safe Mode was to Hit Start Button -> Choose Restart PC and keep pressed SHIFT button simultaneously
that calls a menu that gives you some restore options, along with safe mode options for those who want to read more on How to Enter Safe mode (Command Prompt) on Windows 10 – please read this article.


Once the upgrade was over and all below done unfortunately I've realized her previously installed WIndows 7 is x86 (32 bit) version and the Acer notebook 5736Z where it is being installed is actually X64 (64 bit), hence I've decided to upgrade my dear sis computer to a 64 Bit Windows 10 and researched online whether, there is some tool that is capable to upgrade WIndows 10 from 32 bit to Windows 10 64 bit just to find out the only option is to either use some program to creaty a backup of files on the PC or to manually copy files to external hard drive and reinstall with a Windows 10 64 bit bootable USB Flash or CD / DVD image, so I took my USB flash and used again Windows Media Creation Tool to burn Windows and re-install with the 64 bit iso.

If you're wonder about why I choose to re-install finally Win 10 32 bit with Win 64 bit, because you might think performance difference might be not really so dramatic, then I have to say the Acer notebook is equipped with 4 Gigabytes of RAM Memory and Windows 10 32bit  (Pro) could recognize a maximum of 3 Gigabytes (2.9 GB if I have to be precise) and 1 Gigabyte of memory stays totally unusued all the time with  Winblows 10 32 bit.


I've tried my best actually to not loose time to fully upgrade Windows 7 (32 bit) -> Windows 10 (64 bit) but to make Windows 7 32 bit Windows to use more than the default Limitation of 3GB of memory by using this thirt party PAE Externsion Kernel Patch
which is patching the Windows Kernel to extend the Windows support for PCs with up to 128 GB of memory however it turned out that this Patch file is not compatible with my Windows Kernel version once I followed readme instructions.

It seems the PAE (Physical Address Extension) is supported by default  by Microsoft only on 32 bit Windows Server 10 to read more on the PAE if interested give a look here.

Well that's all folks, the rest I did was to just boot from the USB drive just burned and re-install WIndows and copy my files from User profile / Downloads / Pictures / Music etc. to the same locations on the new installed Windows 10 professional 64 bit and enjoy the better performance.

SEO: Best day and time to write new articles and tweet to get more blog reads – Social Network Timing

Tuesday, June 17th, 2014


I'm trying to regularly blog – as this gives me a roadmap what I'm into and how I spent my time. When have free time,  I blog almost daily except on weekends (as in weekends I'm trying to stay away from computers). So if you want to attract more readers to your blog the interesting question arises

What time is best to hit publish on your posts?

Now there are different angles from where you can extract conclusions on best timing to blog post.One major thing to consider always when posting is that highest percentage of users read blogs in the morning with their morning coffee. Here are some more facts on when web content is more red:

  • 70% of users say they read blogs in the morning
  • More men read blogs at night than woman
  • Mondays are the highest traffic days for avarage blogs
  • 11 a.m. is normally the highest traffic hour for blogs
  • Usually most comments are put on Saturdays
  • Blogs with more than one post a day has higher chance of inbound links and usually get more unique visitors

As my blog is more technical oriented most of my visitors are men and therefore posting my blogs at night doesn't interfere much with my readers.
However, I've noticed that for me personally posting in time interval from 13:00 to 17:00 influence positively the amount of unique visitors the blog gets.

According to research done by Social Fresh – Thursday is the best day to publish an article if you want to get more Social SharesBest-Day-to-Blog-to-get-more-shares-in-social-networks

As a rule of thumb Thursday wins 10% more shares than all other days. In fact, 31% of the top 100 social share days in 2011 fell on Thursday.
My logical explanation on this phenomenon is that people tend to be more and more bored from their work and try to entertain more and more as the week progresses.

To get more attention on what I'm writting I use a bit of social networking but I prefer using only a micro blogging social networking.  I use Twitter to share what I'm into. When I write a new article on my blog I tweet its title with a link to my article, because this drives people attention to what I have to say.

In overall I am skeptical about social siting like Facebook and MySpace because it has negative impact on how people use their time and especially negative on youngsters Other reason why I don't like Friends Networks is because sharing what you have to say on sites like FB, Google+ or "The Russian Facebook" –  Vkontekte are not respecting privacy of your data.


You write free fresh content for their website for free and you get nothing!


Moreover by daily posting latest buzz you read / watched on Facebook etc. or simply saying what's happening with you, where you're situated now etc., you slowly get addicted to posting – yes for good or bad people tend to be maniacal).

By placing all of your pesronal or impersonal stuff online, you're making these sites better index their sites into Google / Yahoo / Yandex search engines and therefore making them profitable and high ranked websites on the internet and giving out your personal time for Facebook profit? + you loose control over your data (your data is not physically on your side but situated on some remote server, somewhere on the internet).

Best avarage time to post on Tweet Facebook, Google+ and Linkedin


So What is Best Day timing to Post, Pin or Tweet?

Below is an infographic I fond on this blog (visual data is originalcompiled by SurePayRoll) and showing visualized results from some extensive research on the topic.


Here is most important facts this infographic reveals:

The avarage best time to post tweet and pin your new articles is about 15:00 h

  • Best timing to post on Twitter is on Mondays to Thursdays from 13:00 to 15:00 h
  • Best timing to post on facebook is between 13:00 and 16:00 h
  • For Linkedin it is best to place your publish between Tuesdays to Thursdays

Peak times on Facebook, Twitter and Linkedin

  • Peak times for use of Facebook is on Wednesdays about 15:00 h
  • Peak times for use of Twitter is from Monday to Thursdays from 9:00  to 15:00 h
  • Linkedin Peak time is from 17:00 to 18:00 h
  • Including images to your articles increases traffic, tweets with images increase visits, favorites and leads

Worst time (when users will probably not view your content) on FB, Twitter and Linkedin

  • Weekends before 08:00  and after 20:00 h
  • Everyday after 20:00 and Fridays after 15:00 noon
  • Mondays and Fridays from 22:00 to 06:00 morning

Facts about Google+

  • Google+ is the fastest growing demographic social network for people aged 45 to 54
  • Best time to share your posts on Google+ is from 09:00 to 10:00 in the morning
  • Including images to your articles increases traffic, tweets with images increase visits, favorites and leads

Images generate more traffic and engagement

  • Including images to your articles increases traffic, tweets with images increase visits, favorites and leads

I'm aware as every research above info on best time to tweet and post is just a generalization and according to field of information posted suggested time could be different from optiomal time for individual writer, however as a general direction, info is very useful and it gives you some idea.
Twitter engagement for brands is 17% higher on weekends according to Dan Zarrella’s research. Tweets posted on Friday, Saturday and Sunday had higher CTR (Click Through Rate) than those posted in the rest of the week.


Other best day to tweet other than weekends is mid-week time Wednesday.
Whether your site or blog is using retweet to generate more traffic to website best time to retweet is said to be around 5 pm. CTR is higher

Outlook Express hotkeys (short keys) list – Use your MS Outlook efficiently

Thursday, March 13th, 2014

I'm foced to use Microsoft Outlook Express daily for my daily work in Hewlett Packard. Thus I decided to learn the hotkeys to make my Mail use more efficient. Here are list of Outlook Express hotkeys, hopefully to be useful to others too:

Print the selected message –  Ctrl+P
Send and receive mail –  Ctrl+M
Delete a mail message - DEL or Ctrl+D
Open or post a new message –  Ctrl+N
Open the Address Book - Ctrl+SHIFT+B
Reply to the message author –  Ctrl+R
Reply to all –  Ctrl+Shitf+R, Ctrl+G (news only)
Refresh news message and headers –  F5
Forward a message - Ctrl+F
Find Text - F3
Find a message - CTRL+Shift+F
Close Message - ESC
Check Names - Ctrl+K, Alt+S
Go to your Inbox - Ctrl+I
Go to the next message in the list - Ctrl+> or Ctrl+SHIFT+>
Go to the previous message in the list - Ctrl+< or Ctrl+SHIFT+<
View properties of a selected message - ALT+ENTER
View the full source of the message - Ctrl+F3
Go to the next unread mail message - Ctrl+U
Go to the next unread news conversation - Ctrl+Shift+U
Go to a folder –  Ctrl+Y
Open a selected message – Ctrl+O or ENTER
Mark a message as read - Ctrl+ENTER or Ctrl+Q
Move between the Folders list (if on), message list, preview pane, and Contacts list (if on) - TAB
Mark all news messages as read - Ctrl+SHIFT+A
Check spelling – F7
Insert signature - Ctrl+SHIFT+S
Send (post) a message –  Ctrl+ENTER or ALT+S
Select all messages –  Ctrl+A

Enjoy 🙂


Top Paying Google Adsense Keywords for 2013 – Increase blog earnings with high paying keywords

Wednesday, July 31st, 2013


Whether you're a blogger and you're trying to earn some extra cash for your daily living via blogging you already know how hard it is. It is not hard it is almost impossible to earn enough from Blog or personal website to make it your primary source of income. With the Crisis the CPC (Cost Per Click) rate of Advertisements and the number of people willing to pay big money for Cost per click dropped down drastically … This means also our earnings as bloggers decreased badly … However there is still a bit of hope to boost a bit Google Adsense Paying revenues, by trying to write articles including certain high payed keywords. Not surprisingly this high pay keywords vary seriously over years. You might be shocked to know that there are some keywords for which Google pays over 100$ per CLICK!!! OMG 100$ per click this sounds unrealistic but according to some rumors online its a fact. I've found on the internet a list of 70 keywords said to make your blog money per click from 179 dollars (highest clickable advertiser pay fee) to 51 bucks at minimum. Actually the reason to write this post was to test if this rumors with so high CPC are true. I will update the post later to tell you whether really top words work or its jus ta big fraud. Here is list of 70 top earning Google Adsense revenue keywords for 2013


How to delete your linkedin account – I don’t want to be LINKED IN!

Tuesday, April 24th, 2012

I don't want to be linkedin, Linkedin is a fake and non-sense time wasting anti-social network

I've decided to delete my linkedin account as I don't see any good in constact connectiodness and being part of many "social" networks which if one thinks in deeply are not social but anti-social.

You just stay at home staring at a screen and it will be like this until the end of your days and even worser for the generations to come. Computer revolution or digital revolution is in reality huge devolutin (devil-lution)

To delete the linkedin account I used a short tutorial provided by This post

How to delete your linkedin account picture

TO reach to your Profile settings, use upper right corner of your browser and follow the menus:

Settings -> Account -> Close your account

Once, trying to delete your account, linkedin will try to manipulate you to stay in Linkedin by pushing some of your contacts, pointing how you will get disconnected from him.
I'm amazed how impudent this guys can be, actually, its not just them. If you have tried or deleted your facebook account before time you will have faced, exactly the same thing. A profile (person picture) which was recently browsed by you will be shown to you and be said you will be unable to connect with him any more. Well who cares if it is God's will we will connect again 🙂

The problem with us modern people is we're so deluded that we have started relying more on technology and human knowledge than to God. For most people who are atheists relying more on technology than on God for their lives seems reasanable However for us Christians putting more trust in technology than in Gods providence for us is sinful and deadly.
I'm starting to get the conclusion, non-technological societies are more happier than technological ones. In that sense, we the Bulgarians are blessed, because technology is not so widely spread.

FreeBSD Jumbo Frames network configuration short how to

Wednesday, March 14th, 2012

FreeBSD Jumbo Frames Howto configure FreeBSD

Recently I wrote a post on how to enable Jumbo Frames on GNU / Linux , therefore I thought it will be useful to write how Jumbo Frames network boost can be achieved on FreeBSD too.

I will skip the details of what is Jumbo Frames, as in the previous article I have thoroughfully explained. Just in short to remind you what is Jumbo Frames and why you might need it? – it is a way to increase network MTU transfer frames from the MTU 1500 to MTU of 9000 bytes

It is interesting to mention that according to specifications, the maximum Jumbo Frames MTU possible for assignment are of MTU=16128
Just like on Linux to be able to take advantage of the bigger Jumbo Frames increase in network thoroughput, you need to have a gigabyt NIC card/s on the router / server.

1. Increasing MTU to 9000 to enable Jumbo Frames "manually"

Just like on Linux, the network tool to use is ifconfig. For those who don't know ifconfig on Linux is part of the net-tools package and rewritten from scratch especially for GNU / Linux OS, whether BSD's ifconfig is based on source code taken from 4.2BSD UNIX

As you know, network interface naming on FreeBSD is different, as there is no strict naming like on Linux (eth0, eth1, eth2), rather the interfaces are named after the name of the NIC card vendor for instance (Intel(R) PRO/1000 NIC is em0), RealTek is rl0 etc.

To set Jumbro Frames Maximum Transmission Units of 9000 on FreeBSD host with a Realtek and Intel gigabyt ethernet cards use: freebsd# /sbin/ifconfig em0 mtu 9000
freebsd# /sbin/ifconfig rl0 mtu 9000

!! Be very cautious here, as if you're connected to the system remotely over ssh you might loose connection to it because of broken routing.

To prevent routing loss problems, if you're executing the above two commands remotely, you better run them in GNU screen session:

freebsd# screen
freebsd# /sbin/ifconfig em0 mtu 9000; /sbin/ifconfig rl0 mtu 9000; \
/etc/rc.d/netif restart; /etc/rc.d/routed restart

2. Check MTU settings are set to 9000

If everything is fine the commands will return empty output, to check further the MTU is properly set to 9000 issue:

freebsd# /sbin/ifconfig -a|grep -i em0em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000freebsd# /sbin/ifconfig -a|grep -i rl0
rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000

3. Reset routing for default gateway

If you have some kind of routing assigned for em0 and rl0, network interfaces they will be affected by the MTU change and the routing will be gone. To reset the routing to the previously properly assigned routing, you have to restart the BSD init script taking care for assigning routing on system boot time:

freebsd# /etc/rc.d/routing restart
default done
add net default: gateway
Additional routing options: IP gateway=YES.

4. Change MTU settings for NIC card with route command

There is also a way to assign higher MTU without "breaking" the working routing, e.g. avoiding network downtime with bsd route command:

freebsd# grep -i defaultrouter /etc/rc.conf
freebsd# /sbin/route change -mtu 9000
change host

5. Finding the new MTU NIC settings on the FreeBSD host

freebsd# /sbin/route -n get
route to:
interface: em0
recvpipe sendpipe ssthresh rtt,msec rttvar hopcount mtu expire
0 0 0 0 0 0 9000 1009

6. Set Jumbo Frames to load automatically on system load

To make the increased MTU to 9000 for Jumbo Frames support permanent on a FreeBSD system the /etc/rc.conf file is used:

The variable for em0 and rl0 NICs are ifconfig_em0 and ifconfig_rl0.
The lines to place in /etc/rc.conf should be similar to:

ifconfig_em0="inet netmask media 1000baseTX mediaopt half-duplex mtu 9000"
ifconfig_em0="inet netmask media 1000baseTX mediaopt half-duplex mtu 9000"

Change in the above lines the gateway address and the netmask to yours corresponding gw and netmask.
Also in the above example you see the half-duplex ifconfig option is set insetad of full-duplex in order to prevent some duplex mismatches. A full-duplex could be used instead, if you're completely sure on the other side of the host is configured to support full-duplex connections. Otherwise if you try to set full-duplex with other side set to half-duplex or auto-duplex a duplex mismatch will occur. If this happens insetad of taking the advantage of the Increase Jumbo Frames MTU the network connection could become slower than originally with standard ethernet MTU of 1500. One other bad side if you end up with duplex-mismatch could be a high number of loss packets and degraded thoroughout …

7. Setting Jumbo Frames for interfaces assigning dynamic IP via DHCP

If you need to assign an MTU of 9000 for a gigabyt network interfaces, which are receiving its TCP/IP network configuration over DHCP server.
First, tell em0 and rl0 network interfaces to dynamically assign IP addresses via DHCP proto by adding in /etc/rc.conf:


Secondly make two files /etc/start_if.em0 and /etc/start_if.rl0 and include in each file:

ifconfig em0 media 1000baseTX mediaopt full-duplex mtu 9000
ifconfig rl0 media 1000baseTX mediaopt full-duplex mtu 9000

Copy / paste in root console:

echo 'ifconfig em0 media 1000baseTX mediaopt full-duplex mtu 9000' >> /etc/start_if.em0
echo 'ifconfig rl0 media 1000baseTX mediaopt full-duplex mtu 9000' >> /etc/start_if.rl0

Finally, to load the new MTU for both interfaces, reload the IPs with the increased MTUs:

freebsd# /etc/rc.d/routing restart
default done
add net default: gateway

8. Testing if Jumbo Frames is working correctly

To test if an MTU packs are transferred correctly through the network you can use ping or tcpdumpa.) Testing Jumbo Frames enabled packet transfers with tcpdump

freebsd# tcpdump -vvn | grep -i 'length 9000'

You should get output like:

16:40:07.432370 IP (tos 0x0, ttl 50, id 63903, offset 0, flags [DF], proto TCP (6), length 9000) > . 85825:87285(1460) ack 668 win 14343
16:40:07.432588 IP (tos 0x0, ttl 50, id 63904, offset 0, flags [DF], proto TCP (6), length 9000) > . 87285:88745(1460) ack 668 win 14343
16:40:07.433091 IP (tos 0x0, ttl 50, id 63905, offset 0, flags [DF], proto TCP (6), length 9000) > . 23153:24613(1460) ack 668 win 14343
16:40:07.568388 IP (tos 0x0, ttl 50, id 63907, offset 0, flags [DF], proto TCP (6), length 9000) > . 88745:90205(1460) ack 668 win 14343
16:40:07.568636 IP (tos 0x0, ttl 50, id 63908, offset 0, flags [DF], proto TCP (6), length 9000) > . 90205:91665(1460) ack 668 win 14343
16:40:07.569012 IP (tos 0x0, ttl 50, id 63909, offset 0, flags [DF], proto TCP (6), length 9000) > . 91665:93125(1460) ack 668 win 14343
16:40:07.569888 IP (tos 0x0, ttl 50, id 63910, offset 0, flags [DF], proto TCP (6), length 9000) > . 93125:94585(1460) ack 668 win 14343

b.) Testing if Jumbo Frames are enabled with ping

Testing Jumbo Frames with ping command on Linux

linux:~# ping -M do -s 8972
PING ( 8972(9000) bytes of data.
9000 bytes from icmp_req=1 ttl=52 time=43.7 ms
9000 bytes from icmp_req=2 ttl=52 time=43.3 ms
9000 bytes from icmp_req=3 ttl=52 time=43.5 ms
9000 bytes from icmp_req=4 ttl=52 time=44.6 ms
--- ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3003ms
rtt min/avg/max/mdev = 2.397/2.841/4.066/0.708 ms

If you get insetad an an output like:

From icmp_seq=1 Frag needed and DF set (mtu = 1500)
From icmp_seq=1 Frag needed and DF set (mtu = 1500)
From icmp_seq=1 Frag needed and DF set (mtu = 1500)
From icmp_seq=1 Frag needed and DF set (mtu = 1500)

--- ping statistics ---
0 packets transmitted, 0 received, +4 errors

This means a packets with maximum MTU of 1500 could be transmitted and hence something is not okay with the Jumbo Frames config.
Another helpful command in debugging MTU and showing which host in a hop queue support jumbo frames is Linux's traceroute

To debug a path between host and target, you can use:

linux:~# traceroute --mtu

If you want to test the Jumbo Frames configuration from a Windows host use ms-windows ping command like so:

C:\>ping -f -l 8972
Pinging with 8972 bytes of data:
Reply from bytes=8972 time=2ms TTL=255
Reply from bytes=8972 time=2ms TTL=255
Reply from bytes=8972 time=2ms TTL=255
Reply from bytes=8972 time=2ms TTL=255
Ping statistics for
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 2ms, Maximum = 2ms, Average = 2ms

Here -l 8972 value is actually equal to 9000. 8972 = 9000 – 20 (20 byte IP header) – 8 (ICMP header)

How to scan for DHCP available servers in a Network range on Linux and FreeBSD

Thursday, December 8th, 2011

GNU / Linux and FreeBSD had a nifty little program (tool) called dhcping . dhcpingsend a DHCP request to DHCP server to see if it’s up and running. dhcping is also able to send a request to DHCP servers on a whole network range and therefore it can e asily be used as a scanner to find any available DHCP servers in a network.
This makes dhcping a nmap like scanner capable to determine if dhcp servers are in a network 😉
To scan an an entire network range with dhclient and find any existing DHCP servers:

noah:~# dhcping -s -r -v
Got answer from:
received from, expected from
no answer

In above’s output actually my Dlink wireless router returns answer to the broadcast DHCP LEASE UDP network requests of dhcping .
On a networks where there is no DHCP server available, the requests dhcping -s -r -v returns:

noah:~# dhcping -s -r -v
no answer

This article was inspired by a post, I’ve red by a friend (Amridikon), so thx goes to him.


How to link WordPress Post or Page Title to external URL website address

Monday, October 24th, 2011

I needed to link a new created WordPress Post to external web page address. So when one clicks over the created post he opens an external website.

I’ve googled around to see how this can be achieved and found ordpress external links plugin
I gave a go of the plugin, but pitily I couldn’t make it work. I decided to try some other methods and after some time I tried another approach. I used the HTML >a href=””< My Post Title </a> as a title and it appeared this simple method prooved working 😉

Here is a small screenshot, from wordpress Add New Post dialog

By the way the information online I’ve found on how this the external link creation for a Page or a Post is made was quite obscure and messy. i wonder why there is no clear explanation on the direct a href link creation, especially since WordPress is a de-facto standard for a blogging platform and nowdays powers up so many websites engines around the world.

How to play VCD videos in Debian Linux

Monday, September 26th, 2011

Totem VCD error occured, could not open location you might not have permissions to open the file

A friend of mine gave me a VCD with some coptic Orthodox Christian exorcism, where there pope was chasing some evil spirits from possessed muslims who came to the Coptic Orthodox Church in egypt. The video was made to be in VCD and as you can expect this did not worked out of the box with Totem and VLC out of the box.
Putting in the VCD video inside my cdrom poped up an error like the one in the header of the post.
In order to make the video play I had to use the old school and now a bit obsolete mplayer.
Hence in order to play the VCD on Debian Linux I had to install mplayer and w32codecs packages first e.g.:

debian:~# apt-get update && apt-get install mplayer w32codecs

Second to play the video from gnome-terminal, I had to switch to the mounted cdrom location /media/cdrom0 and launch the video with mplayer cmd like so:

debian:~$ cd /media/cdrom0/vcd
debian:/media/cdrom0/vcd$ mplayer vcd://2

In some cases it might be necessery to play the video with mplayer command like:

debian:/media/cdrom0/vdd$ mplayer vcd://2 vcd://3

Watching it with mplayer from console has some downsides as I couldn’t make the fast rewind work, but still it’s way better than nothing.
Too bad in Debian Squeeze 6 gmplayer is no longer installable. The gmplayer can probably be installed if mplayer is compiled from source, but I’m too lazy to try it out.
I’ve red also in some forums online that gxine is capable of playing the VCD play nice, but I couldn’t install it from my existing Debian repositories so I did not give it a go.